The present invention relates generally to electronic solid state and integrated circuit devices. More specifically, the present invention relates to apparatuses for dissipating heat generated by such devices.
In the electronics and computer industries, it has been well known to employ various types of electronic device packages and integrated circuit chips, such as the PENTIUM central processing unit chip (CPU) manufactured by Intel Corporation and RAM (random access memory) chips. These integrated circuit chips have a pin grid array (PGA) package and are typically installed into a socket which is soldered to a computer circuit board. These integrated circuit devices, particularly the CPU microprocessor chips, generate a great deal of heat during operation which must be removed to prevent adverse effects on operation of the system into which the device is installed. For example, a PENTIUM microprocessor, containing millions of transistors, is highly susceptible to overheating which could destroy the microprocessor device itself or other components proximal to the microprocessor.
In addition to the PENTIUM microprocessor discussed above, there are many other types of semiconductor device packages which are commonly used in computer equipment, for example. Recently, various types of surface mount packages, such as BGA (ball grid array) and LGA (land grid array) type semiconductor packages have become increasingly popular as the semiconductor package of choice for computers. For example, many microprocessors manufactured by the Motorola Corporation, for use in Apple Corporation computers, employ BGA-type packages. Unlike a PENTIUM microprocessor with a PGA package, which has pins to be installed into a receiving socket, BGA and LGA semiconductor packages include an array of electrical contacts on their bottom surfaces to engage directly with an array of receiving electrical contacts on a circuit board, socket or the like.
In similar fashion to the PENTIUM-type semiconductor devices discussed above, the BGA, LGA and related device packages also suffer from excessive generation of heat. If such heat is not properly dissipated, the chip will eventually fail. As a result, efforts have been made to supply a heat dissipating member, such as a heat sink, into thermal communication with the semiconductor device package, such as a BGA or LGA chip. These heat sinks are commonly machined out of a thermally conductive metallic material and include fins or pins to improve heat dissipation of the heat sink. To improve air flow through these heat sinks, electric fans are commonly affixed directly to the heat sink.
However, in many applications, all that is needed to avoid device failure is improved air flow over the device itself. An additional heat sink assembly is not required. Improved air flow over a device that runs hot and is in need of cooling is commonly achieved by employing motherboard design where the device to be cooled is located at a computer case vent or near the exhaust of a fan, such as one for a power supply within a computer. Since foregoing attempts to bring cooling air over a semiconductor device are difficult to control and are often not matched to the cooling needs of the semiconductor device to be cooled, it is preferably that a separate air flow source be dedicated to the semiconductor device to be cooled.
In the prior art, dedicated air flow to a semiconductor device may be achieved by affixing a fan, such as a ball bearing fan, directly to or proximal to the semiconductor device. However, know fan assemblies and modules are not easily attached directly to a semiconductor device or a socket into which it is installed. Known fan assemblies must either bolted or glued to the semiconductor device for cooling it.
In view of the foregoing, there is a demand for a fan assembly that can be easily affixed to a semiconductor device to be cooled. There is a demand for a fan assembly that is dedicated to a semiconductor device for cooling it. In addition, there is demand for a fan assembly that can be securely affixed to a semiconductor device without the use of fasteners or adhesive.
The present invention preserves the advantages of prior art heat dissipation devices for semiconductor devices, such as microprocessors and RAM chips. In addition, it provides new advantages not found in currently available heat dissipation devices and overcomes many disadvantages of such currently available devices.
The heat dissipation device, for removing heat from an electronic device package, includes a retaining clip having a central member and a first pair of legs depending downwardly therefrom. The retaining clip has a bore with female threading therein. Free ends of the legs are secured to the semiconductor device package. A fan module, having a threaded base portion with a lower edge; is threadably received in the bore of the retaining clip so that the lower edge of the fan module remains in communication with the upper surface of the semiconductor package. As a result, the fan module is secured to the semiconductor device for removing heat therefrom.
In operation, the device is affixed to a semiconductor device by installing the retainer clip over the semiconductor device to be cooled. The retaining clip may be either snapped over the top of the semiconductor device or slid over the semiconductor device from the side. Once the retaining clip is in place over the semiconductor device to be cooled, the fan module with threaded base member is threadably inserted into the bore in the retaining clip. The base is threaded toward the semiconductor device so that the bottom edge of the fan module communicates with the top surface of the semiconductor device. The retaining clip elevates off of the semiconductor device slightly as the fan module is tighten down against the forces of the structure used to secure the retaining clip relative the semiconductor device, such as inwardly turned lips. Alternatively, apertures on the legs of the retaining clip that are respectively engaged with protrusions emanating from a socket into which the semiconductor device is installed. As a result, the heat dissipation device of the present invention can be easily installed without fasteners or adhesive and can be easily removed if necessary.
It is therefore an object of the present to provide a heat dissipation device that can accommodate a wide array of semiconductor device packages.
Another object of the present invention is to provide a heat dissipation device that can provide a dedicated air flow source to a semiconductor device to be cooled.
It is a further object of the present invention to provide a heat dissipation device that can be secured to a semiconductor device without fasteners or adhesive.
It is a further object of the present invention to provide a heat dissipation device that can be easily removed.